The use of “simplified” (reference stress) analysis methods is discussed and illustrated for primary load high temperature design. Elastic methods are the basis of the ASME Section III, Subsection NH primary load design procedure. There are practical drawbacks with this approach, particularly for complex geometries and temperature gradients. The paper describes an approach which addresses these difficulties through the use of temperature-dependent elastic-plastic analysis. Correction factors are defined to address difficulties traditionally associated with follow-up, discontinuity stresses and multiaxiality.
Carter P., Sham T.L., Jetter R.I., “Simplified Analysis Methods for Primary Load Designs at Elevated Temperatures”, Proceedings from ASME 2011 Pressure Vessels and Piping Conference, Baltimore, Maryland, July 2011.